There is little information on Smith. Birmingham Public Library might be able to help.
The main supplier of prison locks today is Chubb Locks Custodial Services - the only part of ASSA Abloy still branded Chubb:
http://www.clcsltd.co.uk/en/site/clcs/Products/
Smith was one of the makers of the ‘Pentonville’ cell lock; Union also seem to have made some.
Gibbons, Hobbs, and in a small way in the past, Union, have been the main other suppliers in Britain.
Few books mention prison locks, though mention is made in some guide books at old museums etc. York museum preserves some old cells (think Dick Turpin, a highwayman from Essex who ended up on a York gallows) with large warded rimlocks. There are a few old police museums which preserve some cell locks.
